Conventionally, a patent document 1 has proposed a semiconductor device in which a heat sink is fixed to a semiconductor module. The semiconductor module is provided by an integral structure in which a semiconductor chip formed with a semiconductor power element and a heat radiation substrate are sealed with a resin. The heat sink has fins and forms a cooling mechanism.
FIG. 20 is a cross-sectional view of the semiconductor device. As shown in FIG. 20, semiconductor chips J1, J2 are formed with semiconductor power elements. A heat radiation substrate J3 includes a copper foil J3a having a desired pattern, an insulated substrate J3b, and a copper foil J3c. The copper foil J3a of the heat radiation substrate J3 is joined to the semiconductor chips J1, J2. A heat sink J4 has fins J4a and is fixed to the copper foil J3c of the heat radiation substrate J3. The semiconductor chip J1 is formed with an insulated gate field effect transistor (hereinafter referred to as the IGBT) as the semiconductor power element. The semiconductor chip J2 is formed with a free-wheel diode (hereinafter referred to as the FWD) as the semiconductor power element.
Signal line electrodes of the semiconductor chip J1, which include a gate electrode, are connected to a lead frame J5 through the copper foil J3a. An emitter electrode of the semiconductor chip J1 and an anode electrode of the semiconductor chip J2 are connected to a lead frame J6 through the copper foil J3a. A heat radiation substrate J9b includes a copper foil 9a, an insulated substrate J9b and a copper foil J9c. Further, a collector electrode of the semiconductor chip J1 and a cathode electrode of the semiconductor chip J2 are connected to the copper foil 9a of the heat radiation substrate J9 through spacers J7, J8, which are made of conductive members. Thus, the collector electrode of the semiconductor chip J1 and the cathode electrode of the semiconductor chip J2 are connected to a lead frame J10 through the copper foil J9a. 
Further, as another example, a semiconductor module provided by an integral structure in which a semiconductor chip formed with a semiconductor power element and a heat radiation substrate are sealed with a resin has been conventionally proposed (see, for example, a patent document 2).
FIG. 21 is a cross-sectional view of the semiconductor module. As shown in this figure, the semiconductor module includes a semiconductor chip J101 and a semiconductor chip J102, and the semiconductor chip J101 and the semiconductor chip J102 are sealed with a resin part J103. The semiconductor chip J101 is formed with an insulated gate field effect transistor (hereinafter referred to as the IGBT) as the semiconductor power element. The semiconductor chip J102 is formed with a free-wheel diode (hereinafter referred to as the FWD) as the semiconductor power element.
A portion between an emitter and a collector of the IGBT and a portion between an anode and a cathode of the FWD are connected in parallel. A signal line terminal J104 is connected to signal line electrodes including a gate electrode of the IGBT. A high-side terminal J105 connects to a collector electrode. A low-side terminal J106 connects to an emitter electrode. Electric connections to external parts are made as the signal line terminal J104, the high-side terminal J105, and the low-side terminal J106 are exposed from the resin part J103.
In particular, the signal line electrodes including the gate electrode of the IGBT are electrically connected to the signal line terminal J104 by a bonding wire J107 connecting between the semiconductor chip J101 and the signal line terminal J104. The collector electrode of the IGBT is directly connected to the high-side terminal J105 through a solder J108. The emitter electrode of the IGBT is connected to an electrode block J110 through a solder J109, and then is further connected to the low-side terminal J106 through a solder J111. An anode electrode of the FWD is connected to an electrode block J113 through a solder J112, and then is further connected to the low-side terminal J106 through a solder J114. Further, a cathode electrode of the FWD is directly connected to the high-side terminal J105 through a solder J115.